Apparatus for the controlled sampling of rain water

ABSTRACT

An apparatus for sampling rain which comprises a container receiving a  saing vessel and provided with a cover having a drive which opens upon detection of a first rain phase and closes at a second rain phase whereby the sampling vessel remains free from contaminants from the atmosphere prior to the rain collection stage.

FIELD OF THE INVENTION

Our present invention relates to an apparatus for the controlledsampling of rain water and, more particularly, to an apparatus forcollecting rain water without contamination by particulates from theatmosphere prior to a rain collection operation and for use in theabsence of operating personnel.

BACKGROUND OF THE INVENTION

The composition of rain water represents a significant indication ofatmospheric contaminants because rain carries such contaminants to theground.

From ecological studies it is known that substances soluble in rainwater are carried to the soil and are picked up by the plant cover, suchcontaminants including, for example, toxic materials such as heavymetals in solubilized form.

Such contaminants may be released into the atmosphere in the form ofdust or aerosols and are picked up by the rain water by mechanicalentrainment or solubilization and are carried therewith to the ground.The systematic monitoring of rain water in the environment forpotentially toxic, noxious, poisonous or other detrimental materials isof advantage in determining the source of these pollutants and isimportant in maintaining an environment substantially free therefrom.

To this end, samples are taken of rain water and are analyzed for theirimpurity contents, generally with the aid of sampling vessels openupwardly and placed at selected locations. The rain water collects inthese vessels and then is removed therefrom for analysis.

It has been recognized that it is of advantage to put out such rainwater collectors or sampling vessels just before the beginning of arainfall to avoid contamination of the vessel with dust particles whichmay otherwise enter the vessel or accumulate therein. However, thisposes a problem since weather is often unpredictable and it frequentlyis not possible to provide operating personnel who can put out therequisite collecting vessel just before the rainstorm in every instance.

Furthermore, it is frequently desired to collect rain water independence upon wind strength of direction because the contaminants froma particular direction may afford a greater level of useful informationthan rain water collected when the wind is blowing from anotherdirection. This has posed an additional stricture upon the individualsresponsible for placing the sampling or collecting vessels.

In fact, with existing methods of rain water collection, considerablemonitoring of the weather, wind direction and like parameters isrequired by alert individuals who must always be available or presentand frequently, apart from the high cost of operating in this manner,the collection is unsatisfactory.

Note should be taken of the fact that the mean-value results which canbe obtained from existing meteorological stations often do not satisfythe requirements as to particularity of collection from rain with thewind blowing from a certain direction. As a practical matter, at leastfor determining the source of certain types of contamination, it isvital to make the sample collection dependent upon the instantaneouswind speed and the instantaneous wind direction.

OBJECTS OF THE INVENTION

It is, therefore, the principal object of the present invention toprovide an improved apparatus capable of automatic sampling of rainwater whereby the disadvantages of earlier techniques can be avoided.

Another object of the invention is to provide an automatic sampler forrain water which precludes contamination by dust particles from theenvironment prior to the onset of rain and which will collect the rainwater for a predetermined duration of a rain phase.

Yet another object of the invention is to provide a sampler for thepurposes described which can facilitate detection of the source ofparticular rain contaminants.

SUMMARY OF THE INVENTION

These objects and others which will become apparent are attained inaccordance with the present invention in an apparatus for sampling therain or for the collection of rain water which comprises a containerenclosing or forming a sampling or sample-collection vessel and providedwith a movable cover which can be shifted by an electrically powereddrive between an open position and a closed position. In the closedposition, the sampling vessel is closed off from the atmosphere andcannot be contaminated by dust particles from the environment. In theopen position a mouth of the sampling vessel is open upwardly to collectrain drops.

According to the invention, electrical control means is provided foroperating the drive means, the control means including a detector forthe beginning of a rain phase and, advantageously, for the end of a rainphase to generate respective signals which are applied to the drivemeans for shifting the cover between the open and closed positions.

Thus the signal at the beginning of the rain phase opens the cover andthe signal at the end of the rain phase closes the cover.

Naturally, more than one vessel may be provided and, in this case, aplurality, for example four, adjacent vessels are used and are providedwith a common cover, advantageously being disposed within a singlecontainer.

According to a further feature of the invention, the rain detector is inan electric circuit with a registering or recording device whichregisters or records signals representing the wind direction from awind-direction sensor or detector. The recording device is placed inoperation at the beginning of the rain phase by an output signal fromthe rain detector and is cut off at the end of the rain phase by theterminal signal therefrom.

According to another feature of the invention, a registering orrecording device is provided for the wind speed, this recording devicebeing likewise started by the start signal from the rain detector andstopped by the terminate signal from the rain detector.

This device can receive an input from a wind-speed sensor or detector(anemometer).

Advantageously the wind speed and wind-direction recorders can becombined in a single two-channel recorder plotting the wind speed andwind direction as a function of time, i.e. a two-channel (signal vs.time) graphic recorder.

It has also been found to be advantageous to include in the circuitryfor the rain detector, a timer which registers the beginning and end ofthe rain phase. This clock can also be integrated in the recordingdevice mentioned above.

The apparatus of the present invention thus enables automatic monitoringat a predetermined location of the release of toxic agents into theenvironment from a particular source or enables the determination of asource by analysis of the collected rain water. The arrangement ofseveral such devices in particular spaced orientation in a networkprovides a systematic regional monitoring of the environment effects ofa toxic-agent source.

BRIEF DESCRIPTION OF THE DRAWING

The above and other objects, features and advantages of the presentinvention will become more readily apparent from the followingdescription, reference being made to the accompanying drawing of whichthe sole FIGURE is a diagram illustrating the apparatus of the presentinvention.

Specific Description

As can be seen from the drawing, the apparatus of the present inventioncomprises a container 2 receiving a sampling vessel 1 and provided atits upper end with a cover 3 which is driven by a motor 7 means mountedon the container 2. The container 2 is so dimensioned that it has roomfor both the vessel 1 and its funnel 4.

The cover 3 may be pivotally connected to the container so as to beswung upwardly by the motor 7 in any conventional manner.

The motor 7 is operated by a control unit 8 which may be amicroprocessor and responds to start and terminate signals from a raindetector 9 which can be of any conventional moisture-sensing type. Thestart signal from the rain detector 9 is supplied to the control unitwhich initiates operation of the motor 7 upon the initial detection ofrainfall to open the cover 3 and allow the rain drops to collect in thevessel 1. When further rainfall is no longer detected, the signal fromthe detector terminates and the control unit reverses the motor 7 toclose the cover 3.

The output of the control unit 8 is also applied to a recorder 10 whichis connected to an anemometer 11 providing an input representing windvelocity to the recorder and to a wind direction sensor 12 likewiseproviding an input to the recorder 10.

The recorder 10 is started and stopped by the control unit at thebeginning and ending of the rain phase and records wind speed from theanemometer and wind direction from unit 12 over this interval. A clock13 is likewise started and stopped by the control unit at these pointsto print on the recording strip of the recorder the starting time andstopping time of the rain collection phase.

A pair of switches 5 and 6 signal the completely open and completelyclosed stations of the cover to the control unit to turn off the motorwhen the cover has reached its fully open and fully closed positionsrespectively.

As soon as the first rain drops come into contact with the rain detector9, the signal applied by the latter to the control unit 8 turns on themotor 7 to raise the cover. Simultaneously, the recorder 10 is energizedand the clock 13 prints on the recording strip the starting time. Thewind velocity and wind direction measurements are recorded. When thecover reaches its maximum open position, switch 5 operates to terminatethe drive of the motor and rain collection continues until the end ofrainfall when the signal from the detector 9 causes the control unit 8to reverse the motor 7 and swing the cover 3 into its closed position.This signal also stops the recorder and induces the clock 13 to printout the time at which stoppage occurred. The switch 6 shuts off themotor when the cover is fully closed.

The sensitive surface of the rain detector can be heated to preventmoisture from the atmosphere, which is not in the form of rain, fromincreasing the length of the collection interval. The moisture on thesurface is thus evaporated immediately after the termination of the rainphase.

SPECIFIC EXAMPLE

The apparatus of the present invention was tested with a vessel 1 in theform of a polyethylene bottle having a capacity of 5 liters. Thecontainer 2 was a rectangular parallelepipedal box of dimensions of600×600×600 mm composed of polyacrylate resin and provided with analuminum cover 3. The funnel 4 had a diameter of 250 mm and was composedof polyethylene.

The rain detector was a rain sensor of type 1515 of the firm ofLAMBRECHT, Gottingen, Germany.

The drive motor 7 was a DC motor operating at 24 volts and 4000 RPM witha stepdown gearing. The recorder was a two-channel X-t recorder of thepaper tape type, one channel registering the wind direction and theother channel the wind velocity on the paper strip. The timedetermination of the rain phase was applied to the tape or wasdetermined by the feed of the paper tape which was not turned off at theend of a rain phase.

We claim:
 1. An apparatus for the controlled sampling of raincomprising:a sampling vessel having an upwardly open mouth adapted toreceive rain drops; a cover disposed so as to be shiftable between afirst position closing said vessel and a second position wherein saidvessel is open to receive rain; first and second signalling means onsaid vessel to signal when each of said positions is reached; a motorconnected to said cover and electrically energizable by signal receivingmeans responsive to said signalling means so as to displace said coverbetween said first and second positions; a rain detector responsive tothe onset and termination of a rain phase and exposed to the atmospherefor producing at least one signal upon the onset of rain and upon thetermination of a rain phase; circuitry between said detector and saidmotor responsive to said signal for energizing said motor at the onsetof a rain phase and closing said cover at the conclusion of a rainphase; a recorder connected to said circuitry and placed in operationupon the onset of said rain phase; clock means for registering the timeof onset of said rain phase and of termination thereof, said clock meansbeing connected to said circuitry; a wind-direction sensor connected tosaid recorder for recording thereon the wind direction upon the onset ofsaid rain phase; and a wind-speed sensor connected to said recorder forrecording thereon the wind speed upon the onset of said rain phase, saidrecorder being two-channel recorder recording the wind speed and winddirection as a function of time of collection of rain by said vessel.